CORE B SUMMARY The overall objective of this program project application is to examine the consequence of monocyte/MF immune modulation on the development and maintenance of MF HIV reservoirs and HIV disease progression, using SIVmac251 infected Indian rhesus macaques. Core B: Immunopathology Core will evaluate the effectiveness of each project's therapeutic strategy for reducing inflammation and the reservoir of SIV in brain and lymphoid organs. Antigens of interest, as they relate to each of the projects, will be examined in necropsy tissues of experimental animals. This will provide a standardized means for evaluating tissues and centralizing the investigations and findings, allowing for greater collaboration between projects, as well as providing for the best use of the specimens. Furthermore, we will evaluate tissues for the presence of productive and provirus in tissues to evaluate the effectiveness of the therapeutic strategies in resolving tissue MFs of SIV infection. We anticipate that these studies will advance our understanding of the role of monocytes/MFs in the development and maintenance of reservoirs of persistent infection, as well as HIV-related disease progression, including HIV-associated neurocognitive dysfunction.